Health officials in Wellington are on alert for cases of meningococcal disease following the death of a 12-year-old girl.

Amanda Crook-Barker died earlier this week just hours after contracting an illness.

Tests are being carried out to determine whether the Evans Bay Intermediate School student had contracted the disease.

Amanda's mother Lisa said her daughter was sick on Monday. She developed a rash at 3pm and by 5pm she had died.

''. . . the aftermath of what it did to her - that wasn't my daughter. It was almost like she had been attacked by the plague, that's how horrific it was,'' Mrs Crook told the Dominion Post.

Another two people, both aged under 20, have been hospitalised with the illness over the past fortnight.

Medical officer of health Annette Nesdale says the illness can escalate very quickly and is urging people to be wary.

She says people need to keep an eye on those with flu like symptoms and check in throughout the day to see that they're okay.

If meningococcal disease was confirmed as the cause of death, it would be the first fatal case in Wellington this year.

There have been 15 other confirmed cases in the region in the past 12 months.

Auckland Regional Public Health Services has received reports of five confirmed cases of meningococcal disease across the Auckland region since last Wednesday.

There have been no reported fatalities and investigations have not found a link between the cases.

Auckland medical officer of health, Dr Andrew Lindsay, said anyone who shows symptoms off the illness should contact their doctor immediately.

"Even if you or your child has been vaccinated, you are still vulnerable to catching the disease, so please see a doctor if you are at all concerned."

Symptoms may include fever, confusion, sleepiness, dislike of bright lights, stiff neck, joint pain and the appearance of a rash. Children and babies may also refuse feeds, can be floppy and experience vomiting.

Nationally, from 2006-10 there were between five and eight deaths a year from meningococcal disease. Last year, there were 13.

A service for Amanda will be held at Evans Bay intermediate School on Saturday morning, followed by a private burial.